SQLSTATE[IM002] SQLDriverConnect: 0 [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified

if (!file_exists($dbName)) {die("Could not find database file.");}
try {
    $dbh = new PDO("odbc:Driver={Microsoft Access Driver (*.mdb)};DBQ=$dbq;Uid=$user;Pwd=$password");
}
catch (PDOException $e)
{
    echo $e->getMessage();
}

Name       : rich1
DsnType    : System
Platform   : 32-bit
DriverName : Microsoft Access Driver (*.mdb)
Attribute  : {DBQ, DriverId, ImplicitCommitSync, Threads...}